clock 1 hour offSupport

My daughter has a Blaze with a wierd problem. We live in the Cental Time Zone and every couple of days her phone resets to show Eastern Time. We live several hundred miles away from the Eastdrn Time Zone, so what is happening here?

T Mobile had her reset the clock function, restore the phone to original factory settings and they even swapped the phone under warranty, but the new one is doing the same thing.

At least it is a hour earlty, not an hour late, but this isn't acceptable for a $400+ phone.